United States Patent 10,905,714: Claim Scope, Patent Strength, Exclusivity and Generic Entry Analysis

US Patent 10,905,714 protects a sterile, low-aluminum L-cysteine hydrochloride solution intended for addition to parenteral nutrition, together with a manufacturing process designed to control oxygen exposure, particulate formation, elemental impurities and container interaction. The patent is narrower than a basic L-cysteine composition patent. Its commercial value depends on whether a competing product uses the claimed concentration, stability profile, vial technology and manufacturing controls.

The strongest claim group covers the finished solution. The second group covers the manufacturing process. Claims 19 through 29 extend the stability period from 12 months to 18 or 24 months and add neonatal or infant parenteral nutrition applications.

What does US Patent 10,905,714 protect?

The patent protects a combination of physical composition, container, quality attributes and shelf-life performance.

Claim element	Principal limitation
Active ingredient	About 50 mg/mL L-cysteine hydrochloride monohydrate, or equivalent L-cysteine, salt or hydrate
Dosage form	Solution in a single-use vial
pH	About 1.0 to 2.5
Aluminum	No more than 100 ppb over the claimed storage period
Visible particles	Substantially free of visually detectable particulate matter
Intended use	Additive for intravenous parenteral nutrition
Stability	At least 12, 18 or 24 months, depending on the claim
Container	Silica-coated glass vial in dependent claims
Other impurities	No more than 20 ppb fluoride and 80 ppb iodide
Admixture stability	Safe for intravenous administration for up to 24 hours after mixing with amino-acid solutions

Claim 1 is the principal composition claim. It does not cover every L-cysteine solution. A product must satisfy the concentration, vial, pH, aluminum, particulate, stability and parenteral-nutrition limitations as a combination.

The claims use “about” for concentration and pH. Courts generally interpret “about” in view of the specification, prosecution history, analytical variability and the technical context. A product slightly outside 50 mg/mL or the stated pH range could still raise infringement issues if the patent record supports a broader construction.

How are the claims structured?

The claims divide into four technical groups.

Composition and stability claims

Claims 1 through 10, 19 through 24 and 27 through 29 cover the finished solution.

Claims 1 and 2 require at least 12 months of stability. Claim 2 specifies storage at approximately 25°C and 60% relative humidity for the aluminum limitation. Claims 7 and 8 add accelerated storage at approximately 40°C and 75% relative humidity for particulate control.

Claims 19 through 22 extend the stability period to 18 months. Claims 27 and 28 extend it to 24 months. Claims 23, 24 and 29 narrow the intended patient population to neonates or infants requiring parenteral nutrition.

Claims 3, 4, 21 and 22 add tight fluoride and iodide limits. These limitations are relevant because elemental and ionic impurities may arise from raw materials, water systems, glass containers, closure systems or processing equipment.

Container claims

Claims 5 and 6 specify a silica-coated glass vial. Claim 14 covers a vial configured to substantially prevent atmospheric oxygen ingress and leaching of heavy metals and anions.

The container limitations create a potential design-around path. A competitor using a polymer vial, a different coated-glass system, or a container with equivalent barrier performance may avoid the express silica-coated-vial limitation in claims 5 and 6. It could still face claims 1, 2, 7, 19, 27 or the process claims if the overall product and manufacturing steps fall within those claims.

Admixture and clinical-use limitations

Claims 9 and 10 require that, after dilution and admixture with specified amino acids, the resulting composition remains safe for intravenous administration for up to 24 hours.

These claims do not broadly claim all parenteral nutrition compositions containing cysteine. They require the accused solution and the specified post-admixture safety result. The claim language also contains apparent spelling errors, including “threononine” and “methoionine.” Their legal effect would depend on the issued patent record and whether the terms are corrected, construed as obvious typographical errors, or treated as limiting.

Manufacturing-method claims

Claims 11 through 18 and 25 through 26 cover a process with the following sequence:

Mix at no more than 30°C.
Use a carrier containing no more than 1 ppm dissolved oxygen.
Adjust pH to approximately 1.0 to 2.5.
Aseptically transfer the solution into a single-use vial.
Reduce headspace oxygen.
Seal the vial.
In dependent claims, reduce headspace oxygen to approximately 1% or less using inert gas overlay and vacuum operation.
Do not use a lyophilizer.
Do not subject the sealed vial to terminal sterilization.
Use a container that limits oxygen ingress and leaching.

The process claims are narrower than typical sterile-fill claims because they require specific oxygen controls and exclude lyophilization and terminal sterilization.

How strong is the patent estate for L-cysteine parenteral nutrition products?

The patent has meaningful product coverage but a limited technical perimeter.

Strengths

The principal strength is the combination of stability and impurity limitations. A competitor may be unable to determine infringement solely by reviewing the label. Aluminum, fluoride, iodide, dissolved oxygen and particulate performance require analytical testing and stability data.

The 18- and 24-month claims increase commercial relevance. A product with a two-year labeled shelf life may satisfy the long-term stability limitations even if the manufacturer does not disclose all formulation details.

The claims also target a specialized clinical product: concentrated L-cysteine for addition to parenteral nutrition. Products used for neonatal and infant nutrition may have less flexibility in aluminum exposure and particulate control, making the claimed specifications commercially relevant.

Limitations

The patent does not claim L-cysteine as a molecule. It does not broadly claim all L-cysteine hydrochloride formulations, all amino-acid admixtures, or all neonatal parenteral nutrition products.

The 50 mg/mL concentration, pH range and single-use-vial requirement narrow the independent composition claim. A competitor could potentially pursue a different concentration, pH, container, impurity profile or shelf-life specification, subject to product quality and regulatory requirements.

The stability limitations may also create proof issues. Infringement analysis would require evidence that the product meets the claimed conditions for the specified time and storage conditions. A product that meets the initial specifications but fails before 12, 18 or 24 months may not satisfy the relevant claim.

What patents protect the formulation and manufacturing process?

Based on the supplied claims, US 10,905,714 contains three principal protection layers.

Protection layer	Relevant claims	Commercial target
Finished solution	1-10, 19-24, 27-29	Marketed 50 mg/mL L-cysteine solution
Sterile manufacturing process	11-18, 25-26	Oxygen-controlled aseptic filling
Container and impurity control	3-6, 14, 21-22	Coated vial and low anion/heavy-metal leachables

The patent therefore operates as a formulation and manufacturing patent rather than an active-ingredient patent. A complete freedom-to-operate review would also need to examine continuation patents, related applications, packaging patents, manufacturing know-how, regulatory exclusivity and third-party patents covering parenteral nutrition systems.

When does US Patent 10,905,714 lose exclusivity?

The patent issued on February 2, 2021, as US Patent No. 10,905,714. Its expiration date cannot be established from the claims alone. Patent term generally runs for 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment, patent-term extension and any terminal disclaimer under 35 U.S.C. §§ 154 and 156.

The relevant commercial timeline is therefore:

Event	Date or status
Patent issued	February 2, 2021
Nominal term rule	20 years from applicable earliest nonprovisional filing date
Patent-term adjustment	Must be verified in the USPTO patent record
Patent-term extension	Must be verified separately
Terminal disclaimer	Must be checked in the file history
Exact expiration	Not determined by the supplied claim text

A patent expiration date should not be inferred by adding 20 years to the issue date. The issue date is not the starting point for ordinary US utility-patent term.

What is the Orange Book status of US 10,905,714?

Patent listing in the FDA Orange Book cannot be determined from the claims provided. Orange Book status depends on whether the patent holder or new drug application holder submitted the patent for listing and whether FDA accepted it as covering the approved drug substance, drug product or method of use.

The claims are directed to a drug product and manufacturing process. A product patent may be eligible for Orange Book listing if it claims the approved drug product or formulation. A manufacturing-process patent generally is not listed in the Orange Book solely because it covers production of the drug. FDA’s listing framework distinguishes drug-substance, drug-product and method-of-use patents from manufacturing patents.[2][3]

For a listed patent, the relevant regulatory consequences include:

A Paragraph IV certification may challenge validity, enforceability or infringement.
A timely patent-holder lawsuit may trigger a 30-month stay of approval under the Hatch-Waxman framework.
A Paragraph III certification may defer approval until patent expiration.
A section viii statement may carve out a patented method of use where the labeling permits a noninfringing use.

The claim set appears more likely to support drug-product coverage than a broad method-of-use listing. Claims directed to use in neonates or infants could present a separate listing question, depending on the approved labeling and FDA’s treatment of the claimed use.

Which companies are challenging US 10,905,714?

No challenger, Paragraph IV filing, ANDA litigation, settlement or district-court proceeding is identified in the supplied material. A reliable answer requires review of FDA Orange Book records, Paragraph IV notices, PACER, district-court dockets and the USPTO file history.

The absence of a challenger in the supplied information does not establish that no challenge exists. Paragraph IV notices are served on patent owners and NDA holders and may precede publicly accessible litigation records.

What generic entry risks exist for the protected product?

Generic entry risk is moderate and depends on the regulatory pathway and product design.

High-risk scenario for the patent owner

An ANDA applicant submits a product that:

Contains approximately 50 mg/mL L-cysteine hydrochloride monohydrate.
Uses a single-use glass vial.
Has pH between approximately 1.0 and 2.5.
Meets the 100 ppb aluminum limit through the labeled shelf life.
Meets the particulate and impurity limitations.
Uses low-oxygen aseptic filling.

That product could face claims 1, 2, 7, 19, 20, 27 and 28. If it uses argon or nitrogen overlay, claims 12, 16, 25 and 26 may also become relevant.

Lower-risk design-around scenario

A competitor could reduce exposure by using:

A noninfringing concentration.
A different container system.
A pH outside the claimed range, if clinically and regulatorily acceptable.
A different manufacturing process.
Terminal sterilization, if feasible and compatible with product quality.
A process with higher dissolved or headspace oxygen, provided the product remains stable.
A product with a different labeled shelf life.

A design-around must be assessed claim by claim. Avoiding the silica-coated-vial limitation does not necessarily avoid the independent claims, which require only a single-use vial.

Does the patent create biosimilar risk?

No conventional biosimilar issue is apparent. L-cysteine hydrochloride is a small-molecule active ingredient, and a competing product would ordinarily proceed through an abbreviated new drug application or another small-molecule pathway rather than a biosimilar application under section 351(k) of the Public Health Service Act.

The competitive risk is therefore generic or follow-on injectable risk, not biosimilar substitution risk. FDA approval would still require demonstration of pharmaceutical equivalence, bioequivalence where applicable, sterility, particulate control, container-closure integrity and compliance with applicable injectable-drug requirements.[4]

How does US 10,905,714 compare with ordinary L-cysteine patents?

Patent type	Typical scope	Relationship to US 10,905,714
Composition-of-matter patent	L-cysteine molecule or salt	Broader chemically, but generally unavailable for an old amino acid
Formulation patent	Concentration, pH, excipients, stability	Closest category
Container patent	Coated glass, oxygen barrier, leachables	Covered in part by dependent claims
Manufacturing patent	Mixing, oxygen control, aseptic filling	Covered by claims 11-18 and 25-26
Method-of-use patent	Use in neonatal or adult nutrition	Narrowly implicated by claims 9, 23, 24 and 29
Regulatory exclusivity	FDA exclusivity period	Separate from patent rights

US 10,905,714 is strongest when the same commercial product practices both the formulation claims and the oxygen-controlled manufacturing claims. It is weaker against a product that changes the concentration, container and process while maintaining acceptable clinical performance.

What litigation and settlement issues should be reviewed?

The principal legal issues are likely to be:

Claim construction for “about 50 mg/mL,” “substantially free,” “safe,” “configured to substantially prevent,” and “equivalent amount.”
Whether the stability limitations are inherent product characteristics or require direct testing of the accused product.
Whether the claims are enabled across the full range of pH, carrier and container configurations.
Whether the “safe for use” language supplies a definite and enforceable limitation.
Whether the manufacturing claims require every listed process step.
Whether the patent owner can prove the required long-term stability before commercial launch.
Whether any continuation patent carries overlapping claims after this patent expires.
Whether a settlement permits an authorized generic, licensed supply or delayed generic launch.

A Paragraph IV case would likely require accelerated work on analytical testing, accelerated and long-term stability data, container-closure studies, elemental impurity data and manufacturing-process discovery.

Geographic coverage and international risk

US 10,905,714 provides rights only in the United States. The same formulation may be protected by related national patents or applications in Europe, Canada, Japan, Australia and other markets, but geographic coverage cannot be inferred from the US claims.

International risk should be assessed separately for:

European Patent Convention designations.
Canada’s drug-patent listing regime.
Japan and South Korea formulation patents.
Manufacturing sites outside the United States.
Importation of an allegedly infringing product into the United States.
Parallel patents covering vial coatings, oxygen control or low-metal amino-acid formulations.

A non-US manufacturing process can still create US exposure if the imported product practices a valid US product claim.

Key Takeaways

US 10,905,714 is a formulation, container and manufacturing patent for stable L-cysteine solutions used in parenteral nutrition.
The core product claim requires approximately 50 mg/mL L-cysteine, pH 1.0 to 2.5, a single-use vial, low aluminum and long-term particulate control.
Claims 19 through 29 extend protection to 18- and 24-month stability and certain neonatal or infant uses.
Claims 11 through 18 and 25 through 26 target low-oxygen aseptic processing, reduced headspace oxygen and non-lyophilized filling.
The patent does not broadly cover L-cysteine, all amino-acid parenteral nutrition products or every cysteine injection.
Generic risk is highest for a substantially identical 50 mg/mL product in a single-use vial with the same stability and impurity profile.
The exact patent expiration date requires the earliest effective filing date, patent-term adjustment, patent-term extension and terminal-disclaimer records.
Orange Book listing, Paragraph IV activity, litigation and settlements are not established by the supplied claims.

FAQs

Can a competitor avoid US 10,905,714 by using a different vial?

Possibly. Claims 5 and 6 specifically require a silica-coated glass vial, but the independent claims require only a single-use vial. A different vial may avoid the dependent container claims while still infringing an independent composition claim.

Does a 24-month labeled shelf life automatically infringe claims 27 through 29?

No. The product must also satisfy the concentration, pH, vial, aluminum, particulate and parenteral-nutrition limitations. The 24-month shelf life is one part of the claimed combination.

Are fluoride and iodide limits central to every claim?

No. The limits apply only to claims that expressly recite them, including claims 3, 4, 21 and 22. They are not required by claim 1 unless incorporated through claim dependency.

Can a manufacturer avoid the process claims by using terminal sterilization?

Terminal sterilization may avoid claims 13 and 17, which require that the sealed vial not be subjected to terminal sterilization. It would not automatically avoid the product claims.

Is a cysteine product for adults outside the patent?

Not necessarily. Claims 1, 2, 9, 10, 19, 20, 27 and 28 are not limited to neonates or infants. The infant and neonatal limitations appear in claims 23, 24 and 29.

References

United States Patent No. 10,905,714, claims 1-29 (issued Feb. 2, 2021).
U.S. Food and Drug Administration. (2023). Approved drug products with therapeutic equivalence evaluations. FDA.
U.S. Food and Drug Administration. (2024). Approved drug product and patent listing requirements under the Hatch-Waxman Amendments. FDA.
U.S. Food and Drug Administration. (2024). Current good manufacturing practice for finished pharmaceuticals, 21 C.F.R. Parts 210 and 211. FDA.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Exela Pharma	ELCYS	cysteine hydrochloride	SOLUTION;INTRAVENOUS	210660-001	Apr 16, 2019		RX	Yes	Yes	10,905,714	⤷ Start Trial	Y				⤷ Start Trial
Baxter Hlthcare Corp	NOURESS	cysteine hydrochloride	SOLUTION;INTRAVENOUS	212535-001	Dec 13, 2019		RX	Yes	Yes	10,905,714	⤷ Start Trial	Y				⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Details for Patent: 10,905,714

Which drugs does patent 10,905,714 protect, and when does it expire?

Summary for Patent: 10,905,714